Carissa holly

Sun

Full sun to partial shade; growth is densest with at least 4-6 hours of direct sun.

Water

Water regularly while establishing; once established, water during prolonged dry spells. Avoid constantly wet soil.

Soil

Well-drained, slightly acidic soil; tolerates clay if drainage is adequate. Alkaline soil can cause yellow leaves.

Height

3-4 ft (0.9-1.2 m)

Spread

4-6 ft (1.2-1.8 m)

Flowers

Small, inconspicuous white flowers in spring; flowering may be sparse.

Foliage

Evergreen. Thick, glossy, dark green leaves, usually with one sharp spine at the tip rather than the several prominent spines typical of Chinese holly.

Growth

Slow to moderate.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   1.9 ft (0.58 m)

3. After 2 years

   2.2 ft (0.67 m)

4. After 3 years

   2.5 ft (0.75 m)

5. After 5 years

   3 ft (0.92 m)

About 7 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Invasive in

the US

Growth rate

Slow

• Water deeply through the first growing season, allowing the soil surface to begin drying between waterings.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the stems.
• Plant with the root flare at soil level; use a raised bed where drainage is poor.
• Feed lightly in spring only if growth is weak or a soil test indicates a deficiency.
• Allow space for its mature width rather than relying on frequent shearing to keep it small.

Pruning. Prune in late winter or early spring before new growth, removing dead or crossing branches and shortening stray shoots individually. For a clipped hedge, trim lightly after the spring flush and keep the base wider than the top.

Late winter

Remove dead or damaged branches and make any necessary shaping cuts before new growth.

Spring

Plant where drainage is good, water thoroughly, and apply mulch.

Late spring

Lightly trim hedges after the first flush of growth, if needed.

Summer

Check newly planted shrubs during dry weather and water deeply when the root area begins to dry.

Autumn

Plant in mild climates while the soil is still warm; avoid heavy feeding or pruning.

Winter

During frost-free dry spells, water young plants if the soil is dry, especially in exposed positions.

• Plant as a low evergreen hedge along a boundary, allowing room for its natural width.
• Use beneath windows as a compact foundation shrub, set far enough from walls to avoid repeated cutting.
• Repeat rounded plants through a mixed border to provide structure among flowering perennials.
• Combine with fine-textured grasses and broad-leaved perennials for foliage contrast.
• Use as a low backdrop to seasonal flowers in a formal or courtyard garden.

Garden styles it suits: Formal, Traditional, Southern, Low-maintenance, Green on green and Winter interest.

Plant it with: Azalea, Camellia, Japanese forest grass, Lenten rose, Lilyturf and Oakleaf hydrangea.

Wildlife: Flowers, when present, attract bees and other small insects. Dense foliage offers cover for small birds, but this cultivar normally provides little or no fruit for them.

• Root rot in waterlogged soil: improve drainage before planting and avoid frequent watering of already damp soil.
• Scale insects: inspect stems and leaf undersides; treat affected plants with a horticultural oil labelled for holly, following temperature restrictions.
• Spider mites in hot, dry conditions: look for fine stippling and webbing, rinse foliage thoroughly, and avoid broad-spectrum insecticides that kill predatory mites.
• Yellow leaves with green veins in alkaline soil: test soil pH, correct unsuitable conditions where practical, and use chelated iron as a temporary treatment if iron deficiency is confirmed.

Holly is considered toxic to people, cats, dogs and horses if eaten, particularly the berries; leaves should not be eaten either. Ingestion can cause vomiting, diarrhoea and abdominal pain, with greater risk from larger amounts. Carissa normally bears little or no fruit, but it should not be treated as an edible plant; its leaf tips are also sharp.

Where it spreads. Chinese holly (Ilex cornuta) has escaped cultivation and is listed as invasive in parts of the southeastern United States, including North Carolina. Carissa normally produces little or no fruit, so its seed-spread risk is much lower than that of fruiting forms.

• Chinese holly (Ilex cornuta)

  Typical Chinese holly grows much larger and usually has several conspicuous, horn-like leaf spines; Carissa is compact and generally has just one terminal spine.

• Dwarf Burford holly (Ilex cornuta 'Burfordii Nana')

  It also has glossy leaves with a terminal spine, but usually becomes taller and commonly carries red berries; Carissa stays lower and normally has little or no fruit.

• Japanese holly (Ilex crenata)

  Japanese holly has smaller, finely scalloped leaves without Carissa's sharp terminal spine, and fruiting plants bear black rather than red berries.

Ilex is the Latin name for holm oak, applied to hollies because of their similar evergreen leaves, while cornuta means horned and refers to the leaf spines.

Propagation. Take semi-ripe cuttings in late summer and root them in a moist, free-draining medium with high humidity. Rooting can be slow; seed does not reliably reproduce the cultivar.

Accepted botanical name

Ilex cornuta

In the US and Canada

Introduced in the lower 48 states.

Native range

China North-Central, China South-Central, China Southeast, Hainan and Korea.

Measured

Soil pH 4.5 to 5.5. Average height 305 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.